Re: Intl. Keysize Limit vs. U.S. Keysize Limit (Was: Re: Hack Lotus?)

["Karl A. Siil" <karl@cosmos.cosmos.att.com>]

At 12:50 AM 1/26/96 -0500, Futplex wrote:
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It would be just as easy to build the intl. version of Notes with 128-bit+spy
>keys, with 40 bits of truly protected key and 88 bits of espionage-enabled 
>key, and then use straight 128 bits in the domestic version.

Does anyone else find it worrisome that given 24 bits of a 64-bit key, the
encryption may not be as strong as the same algorithm with a 40-bit key
(e.g., for a variable key-length algorithm like RC4)? In other words, I
suspect some algorithms might not derive their protection mechanisms equally
from each key bit. What if guess the remaining 40 bits is as easy as
guessing the rest of xyl******?

Just pondering.

                                        Karl